The invention relates to an identification card with a holographic security provision in the form of a large area Lippmann-Bragg holographic recording medium carried by the card.
An identification card of this general type is known, in which the card is provided with a window having disposed therein a hologram which contains a check number in a binary code. The binary code is represented by the presence or absence of a predetermined light radiation at specific points arranged in a predetermined pattern, whereby upon illumination of the hologram with a laser beam, the pattern is reconstructed as an image and by means of a read out device, which includes light sensing elements for the various points of the pattern, such pattern can be decoded as a check number.
This known type of identification card does not provide maximum security against interference, as damage to the hologram disposed in the small window may prevent a reliable decoding of the check number contained therein. Further, security against falsification is not at an optimum as it is possible to punch out the hologram and replace it with a new one having a different check number, without altering the remainder of the information of the identication card.
Further, such type of known identification card possesses additional disadvantages in that the card must be transparent at the portion provided for the hologram and conventional identification cards thus cannot be readily combined with a hologram of this type. Further, the read out of the information stored in the hologram requires a laser necessitating a relatively high outlay for security checking. Further, the reconstructed image displays granulation, as is typical of laser radiation, and which can be disturbing during the read out of the stored information.